1. Field of the Invention
The present invention relates to a package for an electronic component, and, more particularly, to an image sensor package and a method of manufacturing the same.
2. Description of the Related Art
An image sensor is a semiconductor device that converts optical information into an electrical signal. Image sensors are generally classified as charge coupled device (CCD) image sensors or complementary metal oxide semiconductor (CMOS) image sensors. An image sensor is packaged to protect the image sensor's optoelectronics and to permit light to impinge on a light reception or active surface of the image sensor.
A typical image sensor package accordingly includes a housing and a window through which the light is transmitted to the light reception active surface. The image sensor package might further include a lens supported by a lens holder in proper alignment with the active surface of the image sensor. In this case, the lens holder is fitted on an aperture formed on the housing.
An example of such an image sensor package having a lens and a lens holder is discussed in U.S. Pat. No. 6,492,774 B1 to Webster entitled “MOLDED IMAGE SENSOR PACKAGE HAVING LENS HOLDER”, issued on Nov. 19, 2002. In the image sensor package disclosed therein, a screw thread is formed on an outer circumference of a circular lens holder and the housing is provided with a circular aperture in which the lens holder is inserted. A screw thread is also formed on an inner circumference of the aperture so that the lens holder can be thread-coupled within the aperture. This assembly process must be repeated for each image sensor package. Perhaps needless to say, such assembly is pains-taking, time-consuming and costly.
Undesirably, when the lens holder is threaded into the aperture of the housing, friction occurs between the mating screw threads. Because of this screw thread friction, the mating screw threads tend to abrade. The abrasion produces free particles within the housing's aperture. Such free particles obscure the optical path and produce uncompensable errors in the image sensing process. Furthermore, it is difficult precisely to control the threading of the lens holder into the aperture. As a result, the focus of the lens requires later adjustment in order to achieve optimal optical alignment and imaging performance.
Therefore, there is a need for an image sensor package that prevents undesirable free-particulate production during manufacture. There is also a need for a manufacturing method in which a plurality of image sensors can be simultaneously assembled into corresponding packages.